<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="../react18/react.development.js"></script>
    <script src="../react18/react-dom.development.js"></script>
    <script src="../react18/babel.min.js"></script>
</head>
<body>
    <div id="app"></div>
    <script type="text/babel">
    // 这个是根组件
    class App extends React.Component{
        state={
            count:0
        }

    render(){
        console.log("----render----");
        const {count}=this.state;
        return(
            <div>
            <button onClick={this.handle}>+</button>
            <p>{count}</p>
            </div>
        )
    }
        // 事件函数
        handle =()=>{
            // 直接修改state不会重新调用render不会重新渲染 
            // 这个写法是错的，不会随便修改state
            this.state.count ++;
        }

}
    const root=ReactDOM.createRoot(document.getElementById('app'));
    root.render(<App/>)
    
    
    </script>
    
</body>
</html>